<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body {
            font-size: 22px;
        }

        .outer {
            width: 500px;
            background-color: skyblue;
            border: 1px solid #000;
            padding: 20px;
            position: relative;
        }

        .box {
            width: 200px;
            height: 200px;
        }

        .box1 {
            background-color: #cd3c3c;
        }

        .box2 {
            background-color: #aecd3c;
            position: fixed;
            top: 0;
            left: 0;
        }

        .box3 {
            background-color: #6a3ccd;
        }
    </style>
</head>

<body>
    <div class="outer">
        <div class="box box1">1</div>
        <div class="box box2">2</div>
        <div class="box box3">3</div>
        <div class="style" style="height: 2000px;"></div>
    </div>

</body>

</html>